Sodium Alginate-Assisted Synthesis of PdAg Bimetallic Nanoparticles and their Enhanced Activity for Electrooxidation of Ethanol

Palladium and palladium-silver bimetallic nanocrystals have been synthesized hydrothermally by using environmental-friendly sodium alginate as the stabilizer and reducing agent. The pure palladium nanoparticles were spherical-like possibly due to the principle of the lowest surface energy, however, the formation of bimetallic palladium-silver nanoparticles was much more complicated, which was thinner and more irregular nanostructures than pure palladium nanoparticles. Electrochemical measurements showed that the electrocatalytic activity toward ethanol oxidation was increased first with the increase of silver content in bimetallic nanoparticles, from pure palladium of around 1070[Formula: see text]mA/mg, to PdAg-20 of 1160[Formula: see text]mA/mg and to PdAg-10 of 1750[Formula: see text]mA/mg, and declined greatly at a high content of silver, approximately 279[Formula: see text]mA/mg. Electrochemical stability test showed that PdAg-10 and PdAg-5 were the best and worst among four palladium-based samples, respectively. Based on the experimental data, the formation mechanism of pure palladium and palladium-silver bimetallic nanoparticles and the structure-property relationship of these samples have been discussed.

Platinum and platinum based nanoalloys synthesized by wet chemistry

Platinum nanocrystals and their derivatives with palladium and cobalt are of fundamental interest due to their wide field of application in chemistry and physics. Their properties are strongly dependent on their shape and composition. However the chemical route is far from allowing control of both shape and composition. In this paper, we show both experimentally and theoretically the important role of the interaction of small adsorbed molecules on the shape but also on the composition. This has been studied by comparing the case of pure palladium and platinum nanocrystals and the case of PtPd and PtCo nanoalloys synthesized by the liquid–liquid phase transfer method.